FR2620533A1 - METHOD AND DEVICE FOR DETECTING THE FILLING OF A CLARIFICATION SWINGER OF NUCLEAR FACILITIES - Google Patents

Abstract

The invention relates to a device and a method for detecting the filling and / or loading of the drum of a clarification wringer supplied with radioactive fluids from nuclear installations, as well as for researching the nuclear combustion of fuel elements. The device according to the invention is characterized in that it comprises: - a gamma spectrometer 28, the detector 26 of which is arranged at the height of the drum 6 of the clarification wringer 2 to detect gamma radiation, and - an installation for operation 30 to detect the peak height and peak width of the lines of the predetermined particular wastewater nuclide gamma spectra and / or to determine the amount of filler from the height and width values detected, as well as to detect the nuclear combustion of fuel elements. Application for measuring the nuclear combustion of fuel elements.

Description

océdé and device for detecting the filling of a wringer

  clarification of nuclear installations.

  The invention relates to a method for detecting filling and / or

  the drum load of a food clarification wringer

  e in radioactive fluids from nuclear installations, as well as research into the nuclear combustion of fuel elements,

  the use of the process for the measurement of

  of combustible elements, as well as a device for the

of this process. -

  DE-OS 3522126 discloses a device for

  radioactive waste water from

  in which the wastewater is treated in a clarifying filter wringer which is monitored against

  overload by a level measuring probe operating without

tact.

  DE-PS 3241624 discloses a method and a device

  the determination of the solid load of the drum of a drum.

  reuse. The spinning drum and an additional body connected to the drum

  bour are set in proper oscillation, and then the frequency is measured.

  quence of the own oscillations depending on the load in solids

  or a magnitude differentiable from the frequency.

  DE-OS 2552568 relates to a signaling device of the

  maximum permissible sludge volume filling of the rotating drum

  tif of a separator. The position of the phase boundary between the media to be separated in the separator drum is detected

by photoelectric barriers.

  DE-OS 3301113 relates to a method and a device for separating

  paration of environments. The phase boundary of the media to be separated

  is detected in a transition zone with multiple zones of

  with several interrogation radiations which can be

  for example, light radiation.

  DE-OS 3622886 relates to a wringer for separating

  with fluids, for example fission products from

  dissolved nuclear fuel. The amount of solids is detected

  using a dyrnamometric box

  weigh the drum of the wringer and its contents during the

  ioning. It is already known to calculate the nuclear combustion of fuel elements from the gamma spectrum of fission products, in

  Including a fuel element to be analyzed in a measuring chamber

  re shielded by lead screen, squeezing it at its ends

  in a positioning device, and by passing it

  i-step in front of a collimator plummet and a detector ("Measurement of nuclear combustion by experimentation of null power by

  samma-spectrography "by J. Knot and Others," Atomkernenergie ", 13th

  year (1980>, pages 67 to 71). In the case of this known process,

  The disadvantage is that the measurement of nuclear combustion

  It can be overcome by the special geometry of the fuel element

  ible. In addition, this type of measurement of nuclear combustion is.

  Linked to a relatively high expense.

  It is an object of this invention to provide a novel method of

  detection of the filling and / or the load of the drum of an esso-

  a clarification machine supplied with radioactive fluids as well as for the measurement of nuclear combustion of fuel elements can be implemented with a low expenditure; she must

  Also provide a device for the implementation of this procedure.

  the. This goal is achieved thanks to the fact that we measure spectroscopically

  The gamma radiation of fluids and / or solids contained

  lans and the gamma spectrum is quantitatively evaluated for one or more

  nuclides for the detection of the respective quantity of

  pleating and / or charging. A particular use of the process, by which the nuclear combustion of fuel elements can be detected, is also part of the invention, as well as a device for carrying out the method.

  Thanks to the method according to the invention, the filling can be detected.

  ge and / or non-contact load in the wringer, which is very

  advantageous from a technical point of view and from the point of view of

  curity. Measurement of gamma activity can be carried out by

  of a commercial gamma spectrometer. The process is sufficient

precisely.

  The method can also be used to advantage for

  the combustion of fuel elements and other

  my implementation. This allows for example a control of

  corresponding operating income. Special geometries of

  the fuel element can not distort the fuel

  nuclear power. It is particularly advantageous that the measurement of the nuclear combustion can be carried out at the time of the new reprocessing of the fuel of burned fuel elements.

  means of an operation to clarify the fuel solution

  ble by means of a clarification wringer. We can give up

  additional devices for the treatment of pencils

fuels.

  The device used for the implementation of the method is robust

  e and not very sensitive to disturbances.

  other advantageous and useful forms of the goal solution

  elm to the invention are characterized in the description

  uivante. The invention will be described below in more detail with reference to the accompanying drawings, in which: FIG. 1 schematically represents a device for detecting the filling and / or the load of a

  drum of clarification wringer powered by fluid

  radioactive nuclear facilities as well as for the detection of the nuclear combustion of fuel elements using the clarification wringer

  supplied with radioactive fluids from nuclear

  res, and Figure 2 is a diagram representing the

  activity as a function of time and the state of

  filling and / or charging the clarifiers wringer

  tion. FIG. 1 represents in section a clarification wringer 2

  with a housing 4 and a drum 6 which is driven by a drum 8.

  The drum has on its upper face an annular groove which communicates with the cavity 14 of the drum by holes 12

lirigated outward.

  In feed tube 15 for radioactive wastewater

  rises inside the annular groove 10.

  A derivation 16 is provided for the clarified fluid fraction

radioactive fluid brought.

  A solid fraction forming a cake 24 shifted on the inner wall.

  drum is rinsed with water by a 20-gauge spear.

  Sprayers 18 and out of the casing 4 downwards with the rinsing water through an outlet pipe 22. By rinsing the solid sedimented, the speed of rotation of the drum is strongly

  reduced, the largest fraction of the fluid in the drum

  bour still in a receiver duct eL being able to

flow by the bypass 16.

  In the region of the drum is disposed a detector 26 of a spectrophotometer

  gamma meter which is connected to an operating unit 30,

  the so-called intelligent calculator, for the detection of the quantities of fluid supplied (Lotale charge) as well as the quantity of the sedimented solid fraction and / or

  the fluid fraction absorbed from the gamma rays.

  The detector is, as is known per se, behind a collar

  plumber and is mounted advantageously movable along the

  Lambour on a stick 34 or similaixre (see arrow 36). We can also

  lemient provides several detectors which are advantageously

  one above the other along the drum and who can

  In addition, they may be mounted movably (not shown).

  The supplied radioactive fluid contains inter alia as a fraction of

  Cesium-137/134, cerium-144 and rhodium-106 are converted into ruthenium-106. The composition of the fluid as well as

  the relative amounts of the components are known. During the

  of the clarification centrifuge, it is therefore possible to detect

  the amount of fluid supplied, by measuring and interpreting the

  gamma rays Cs using spectrometer 28 and the unit of operation

30.

  As soon as the solid sediments, the gamma-rhodium-106 line increases

  te in the gamma spectrum. Because the solid fraction is

  at around 40% rhodium-106, we can detect

  gamma ray interpretation the amount of sedimented rhodium-106

  and then, from this, the amount of sedimented solid.

  The known gamma lines are then interpreted in a known manner.

  with regard to the height of the point and the width of the point

  te to determine the respective quantities of nuclides.

  By a continuous loading of the wringer into radioactive fluid and

  extraction of the clarified fraction by the derivation 16, the

  sium (Cs) is extracted at the same time. The gamma-Cs lines become

  are then relatively smaller for a growing sedimentation

  of the solid fraction, while the rhombic gamma lines

  dium (Rh) increase due to the growth of the solid cake 24.

  Instead of cesium and / or rhodium, it is also possible to evaluate

  correspondingly troscopically other nuclides pre-

in the radioactive fluid.

  Figure 2 shows the variation of a filling measurement /

  load of the drum of the wringer. The values and measurement parameters

  re can be drawn from Figure 2. First, the activity increases

  quickly in correspondence with the amount of fluid brought

  radioactive until complete filling of the drum (curve A).

  Cesium-137/134 and cerium-144 do not sediment. By a

  sure, for example of the gamma spectrum of cesium, we can

  this fact deduces the amount of fluid supplied.

  Rhodium-106 sediment. It is detected that the total activity increases

  by the sedimentation cake that forms (curve B) while

  that the portion of activity of the fluid fraction remains practically

  constant and only slightly decreases, and in fact

  5% for the maximum load (in the drawing, after a

clarification of about 6 hours).

  When, after completion of the clarification operation, it is

  draws the fluid, the activity decreases in correspondence - see

  C. Curve D represents the rapid drop in activity during the following rinsing phase in which the sedimented cake is

rinsed and evacuated from the drum.

  The process just described and the previous device con-

  come for the detection of nuclear combustion of combustible elements. In order to detect nuclear combustion, during the

  initial phase of feeding or filling (curve A of the di-

  gram of Figure 2), the gamma spectrum of cesium and / or

  Using the spectrometer 28, the intelligent calculator 30 calculates. then peak heights and peak widths from the gamma gamma-ray lines and detects from these

  quantities, in a manner known per se, nuclear combustion.

Claims (11)

  1. Method for detecting the filling and / or the charge of the drum   beating of a clarification wringer powered by radio-fluids. nuclear plants,   characterized in that spectroscopically the radiation is measured   gamma flow of the fluids and / or solids con-   quantify the gamma spectra for one or more nuclear   for the detection of the respective quantity of filling and / or charge.   2. Method according to claim 1,   characterized in thatorn measures, in a manner known per se, the height   tip width and the peak width of the gamma lines, and   Lermine from these quantities the amount of nuclide or nu-   clides, from which it is detected, from the quantity or quantities   detected nuclides, the total amount of charge and / or the   amount of solid fraction and / or the amount of fluid fraction.   3. Method according to one of claims 1 eL 2,   characterized in that for detecting the filling amount tL-   the gamma ray of cesium-137/134 dissolved in the radioactive fluid.   4. Method according to one of claims 1 eL 2,   characterized by the fact that, in order to detect the solid fracture, one evaluates   read the gamma line of rhodium-106 which is formed by ruhlenlun-1C.   contained in the solid fracture of the fluid.   5. Method according to one of claims 3 and 4,   characterized in that the gamma lines of the sium-137/134 and rhodium-106.   6. Use of the method according to one of the preceding claims   to measure the nuclear combustion of fuel elements,   characterized in that spectroscopically the radiation   of fluids and / or solids contained in during the filling phase in a measurement phase   beginning of the filling and the beginning of a sedimentation, and that   the gamma spectrum obtained to detect the nu-   Cleaire. 7. Process according to claim 6, characterized in that the gamma spectrum of cesium and / or cerium is measured.   8. Method according to one of claims 6 and 7,   characterized by measuring, in a manner known per se, the height   the tip width and the peak width of the gamma lines and detects   from these quantities, in a manner known per se, the combustion nuclear power.   9. Device for implementing the method according to one of the   preceding vendications, with a clarification wringer for the treatment of radioactive fluids of nuclear installations, characterized in that it comprises:   a gamma spectrometer (28) whose detector (26) is   at the drum (6) of the clarification wringer (2) for detecting gamma radiation, and   an operating installation (30) for detecting the height   peak and the peak width of spectral lines   nuclides gamma specific wastewater predefined   born and / or to determine the amount of charge from   their detected height and width, as well as for detecting   nuclear combustion of fuel elements.   10. Device according to claim 9, characterized in that the detector (26) is mounted movably along drum (6).   11. Device according to one of claims 9 and 10,   characterized in that a plurality of detectors are arranged along drum (6).